Stmicroelectronics S.a.

Sgs-Thomson Microelectronics S.a.

Philippe Merceron

Andr&eacute; Bremond

André Bremond

Choukri Karoui

A series device for protection against a heating of aparallel protection element of an equipment of a telephone line, including a bi-directional cut-off element, of normally on state and placed in series with the parallel protection element, a temperature detection element, and a switching element adapted to turning off the cut-off element when the temperature detected by the detection element exceeds a predetermined threshold.

Circuit for protection against heating of a protection element of equipment

A device of protection of at least one circuit supplied by a voltage obtained from at least one inductive element, including a switch for short-circuiting the supply provided by the inductive element, and circuitry for turning on the switch when the supply voltage exceeds a predetermined threshold and for turning it off when it is smaller than the threshold.

Device for protecting loads supplied by an alternator

The present invention relates to a control circuit of a vibrating membrane excited by a solenoid in series with a d.c. supply and a controlled switch. A capacitor is disposed across a series circuit including the solenoid and the switch associated with opening means in the vicinity of a zero crossing of the current in the inductance.

Control circuit for a vibrating membrane

A circuit of electric arc generation from an A.C. voltage, includes circuitry for making the electric arc frequency substantially independent from possible amplitude variations of the A.C. voltage.

Electric arc generation circuit

The present invention relates to a system for protecting against overloads in a telephone system. The telephone system includes a telephone exchange, a ringing device and an interface, coupled to receive input signals on subscriber lines. The input signals are forwarded to either the telephone exchange or the ringing device depending upon the operating mode of the telephone system. The telephone line supplies a signal indicating the operating mode. A single protection device is coupled between the input of the subscriber lines and the interface. The protection device is controlled by the operating mode signal, and includes logic for protecting both the ringing device and the telephone exchange.

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Vernon, France

Philippe Merceron